Field of the Invention
The present invention relates to an exposure control apparatus for a camera capable of performing photographing at an exposure value which is satisfactory to some extent for all objects.
A typical conventional exposure control apparatus is disclosed in Japanese Patent Disclosure No. 57-42026 (U.S. Pat. No. 4,412,730). There is described a multi-photometric apparatus in which an object is divided into a plurality of areas, and the plurality of areas are photometrically measured to output a plurality of photometric outputs respectively corresponding to the plurality of areas. One of a maximum brightness level, an intermediate brightness level between the maximum brightness level and an average brightness level, the average brightness level, an intermediate brightness level between the average brightness level and a minimum brightness level, and the minimum brightness level is selected based on the maximum brightness level to control the exposure. Japanese Patent Disclosure No. 61-173226 discloses a technique for detecting a back light state from a spot photometric value at a central portion of a field of view and an average photometric value for the entire field of view and performing a caution display or correcting an exposure value, wherein a detection error can be eliminated by using an object distance information in back light detection.
These conventional examples can cope with only limited object patterns since they recognize object patterns using microcomputers, or perform erroneous detection to produce an undesired photograph. When it is desired that a correct exposure control is performed for many object patterns, the object patterns and brightness levels cannot be standardized, thus resulting in a large program size and an increase in calculation time. In addition, even if a photograph is obtained as designed by a manufacturer, evaluation of photographs depends on individual senses. Therefore, the resultant photographs are not always best to the respective users.